TDS meter question

[anramitaco]

I use distilled water for my CPs and some orchids, but after reading many threads on here (and elsewhere) about the possibility of using low TDS tap water for Nepenthes, I was curious to find out how my own measured up. I went ahead about bought an inexpensive TDS meter and tested the tap water. It read 55 ppm. I've tested a few different times and it reads 55-56 every time.

Does anyone own this meter? Is it trustworthy? Perhaps I'm not giving my city/state enough credit, but I'm having a hard time believing that the water here is that pure...

If anyone from the New Haven, CT area wants to weigh in, please do!

 

[Radagast]

Interesting. I do not have that specific model, however I do own 2 TDS meters. One was a cheap one bought from Amazon; the 2nd came along with an expensive multi stage water filter. I tested them both out on distilled water, tap water, as well as a solution of Maxsea with water. Oddly enough I got similar readings from each, they were only off by single digits.

I believe all (or at least many) counties publish annual data about the water supply which may include TDS readings. I'd check that out. If you have a cheap, common Nepenthes you wouldn't mind experimenting on you could try watering it with your tap water and see what happens.

 

[Stranger]

Don't own the meter and not from your area, but my understanding is that if you get some DI water and regular table salt you can mix up solutions with a known TDS, then see how the meter goes in measuring those?

Heh, that's what I get for posting before reading the full description, looks like that *is* how they calibrate the meter...

 

[anramitaco]

Hmm. I had a look at my water quality report and it doesn't list the total TDS, but breaks everything down by contaminant. Quickly adding that up, I got 49.3, give or take (math was never my strong suit). I've been watering some N. ventricosa I got from Lowe's, a hideous N. spath x (talang x spec) that I'm happy to sacrifice, and my beloved but vigorous N. maxima x aristo for about two weeks now and haven't noticed any ill effects, but two weeks may be too soon.

 

[Not a Number]

I have that meter. That company makes reliable products. It can be recalibrated. Buy a calibration standard off Amazon if you are concerned or take a sample of water to an aquarium store and have them test it. I checked mine after 3 years and it was still within specifications.

 

[anramitaco]

Thanks, NaN. I'm glad to know this one is reliable. I just tested it on some mineral water and the ppm was predictably high, so perhaps my tap water is low in TDS after all.

 

[BobZ]

I looked at your New Haven water quality data and agree that your TDS reading of 55 ppm seems to be in reasonable agreement with the published report. What comes out of your faucet after transit through miles of pipe may be expected to be a bit higher in TDS than at the source. I would feel safe to use the tap water on my plants. I might let the water stand in an open container for a day to allow some of the added chlorine to gas-off. Of course, rain water is a great alternative.

 

[Axelrod12]

I could shed some light here. I've lived in New Haven for the past year and a half and Milford for a while before that (same water supply). Over the past 3-4 years I've tested our water fairly consistently between 40-65ppm. It is consistent with the water quality reports. Perhaps more helpful, I water all of my potted Sarracenia with the hose and have for over a year with no ill effects. They do get flushed occasionally though which I would recommend if you do this with your Neps.

I've used the meter you linked along with a couple others. They all seem to be fairly accurate.

 

[anramitaco]

Thank you both for verifying this information. I'm going to take the plunge!